IC component separating method and separating apparatus

ABSTRACT

A method and apparatus for separating an IC component (1) from a board (3). The method includes the processes of positioning a tool (21) just above the IC component, thereafter moving the tool down into a specified position, making the tool cover the IC component that is mounted on the board via an adhesive material, solder, or paste, and separating the IC component from the board by turning the tool. Through these processes, the IC component can be separated with a relatively small force, so that cracking of the IC component and damage to the board can be suppressed to a minimum.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a separating method and separatingapparatus for separating an IC (Integrated Circuit) component mounted ona board of a flat panel display such as an LCD (Liquid Crystal DisplayDevice) and a plasma display or a printed board for an electroniccircuit from the board.

2. Description of Related Art

Lately, flat panel displays have been used for many products by virtueof their compactness and the like, and their performances are improvingday by day, so that low-price high-performance products employing flatpanel displays are appearing. Flip-chip mounting, CSP (Chip SizePackage), BGA (Ball Grid Array) and so on employing a bare IC chip areincreasingly used for electronic circuits responding to the demand forthe compacting of the circuits.

The IC components mounted on the boards of electronic equipment and flatpanel displays include a certain number of defectives, and for thereason of a failure in mounting, it is required to perform repair byremoving the IC components. Attempting an improvement in productivity ofrepair is an important subject.

As a prior art method for bonding an IC component onto the board of aflat panel display and the printed board of electronic equipment,Japanese Examined Patent Publication No. 62-6652 and so on disclose theflip-chip system bonding method of interposing an anisotropic conductivefilm on the electrodes of the board of a flat panel display, mounting anIC component on the film and bonding the component by performing athermocompression bonding by means of a pressurizing tool. JapaneseUnexamined Laid-Open Patent Publication No. 4-302444 and so on disclosethe contents of the bonding method.

In general, as a method for bonding the electrodes of the board of aflat panel display and the bumps of an IC component together, there isperformed the processes of holding the board of the flat panel displayon a stage, mounting the IC component on the board of the flat paneldisplay and performing thermocompression bonding. Normally, in anattempt at improving the productivity, the thermocompression bonding ofthe board of the flat panel display and the IC component is performedsubstantially in one process, through which the adhesive of ananisotropic conductive film has been hardened for the completion ofbonding.

However, the IC components used in this case include a certain number ofdefectives, and the defective IC components have been repaired in thesubsequent process. Particularly when mounting an IC in a bare state bythe flip-chip system, the necessity of this repair work becomessignificant since the IC characteristic test cannot be sufficientlyperformed. In particular, the fraction of defective products becomesproportional to the exponentiation of the defectives of IC components,and therefore, in a high-resolution display (having many lines), thedrive use IC components to be bonded increase in number, meaning thatthe repair is the important subject.

As shown in FIG. 14A and FIG. 14B, when an IC component 1 is bonded bycompression bonding, the IC component is firmly bonded to a board 3comprised of the board of the flat panel display or of a circuit boardby an anisotropic conductive film 2. Therefore, when performing repairfrom this state, the conventional manner has had the steps of removingthe IC component 1 from the board 3 by means of a spatula-shaped jig 11(see FIG. 14A) or tweezers 12 (see FIG. 14B), softening the anisotropicconductive film 2 by means of a solvent 13 and removing the anisotropicconductive film 2 from the board 3 by scraping away the film 2 by meansof a cotton swab 14 as shown in FIG. 14C.

However, with the jig 11 or the tweezers 12, a strong force is locallyapplied to the IC component 1, and this has generated cracks in the ICcomponent 1 and damage to the board 3.

In the case of an IC component whose bumps are bonded by means of an Agconductive paste or solder, the removal of the IC component has beendifficult after performing sealing.

As disclosed in the prior art reference of Japanese Patent Laid-OpenPublication No. HEI 4-76929, it is possible to test the adhesive in asemi-hardened state and perform repair as shown in FIG. 14B. However,when the sealing material is introduced into a space between the ICcomponent and the circuit after the test, it is very difficult to repairany occurring defects.

As shown in FIG. 15, in the case of the IC component 1 of BGA or thelike, balls 4 located on the board 3 side and on an IC component la sideare connected generally by solder 5. In such a case, it is difficult tophysically separate the IC component with a force applied in this state.If it is attempted to indirectly melt the solder by heating a tool forbonding the IC component 1, then a considerable time has been consumeddue to the bad heat conductivity of the IC component 1, resulting in alow productivity.

Accordingly, the object of the present invention is to provide an ICcomponent separating method and separating apparatus capable of easilyseparating an IC component from a board when separating the IC componentfrom the board after bonding the IC component to a circuit board, a flatpanel display board or the like.

SUMMARY OF THE INVENTION

In order to solve the aforementioned problems, the present invention isconstructed as follows.

According to a first aspect of the present invention, there is providedan IC component separating method for separating an IC component mountedvia a bonding intervenient on a board from the board, comprising of:

making at least a pair of opposite contact surfaces that are formed on atool and contact the IC component mounted on the board;

softening the bonding intervenient by heating the IC component or abonded portion of the IC component and the board; and

separating the IC component from the board by turning the tool so as totwist the tool relative to a bonded surface on which the IC component isbonded to the board.

According to a second aspect of the present invention, there is providedan IC component separating method based on the first aspect, wherein thebonding intervenient is an anisotropic conductive film.

According to a third aspect of the present invention, there is providedan IC component separating method based on the first or second aspect,wherein the contact surfaces of the tool is made to contact the ICcomponent with the tool heated, the bonding intervenient is softened byheating the IC component or the bonded portion of the IC component andthe board through heat conduction from the tool, and then the ICcomponent is separated from the board by turning the tool so as to twistthe tool with respect to the bonded surface on which the IC component isbonded to the board.

According to a fourth aspect of the present invention, there is providedan IC component separating method based on any one of the first throughthird aspects, wherein the IC component is attracted by vacuum suctionfrom the tool when separating the IC component from the board by turningthe tool.

According to a fifth aspect of the present invention, there is providedan IC component separating method based on any one of the first throughfourth aspects, wherein the IC component or a bonded portion of the ICcomponent and the board is heated with infrared light from a rearsurface of an IC component mounting surface of the board when separatingthe IC component from the board by turning the tool.

According to a sixth aspect of the present invention, there is providedan IC component separating method based on the fifth aspect, wherein ashield plate having an opening is arranged between an infrared lightapplying device and the board, and the infrared light is applied throughthe opening to only the bonded portion to be separated when heating theIC component or the bonded portion with infrared light.

According to a seventh aspect of the present invention, there isprovided an IC component separating method based on any one of the firstthrough sixth aspects, wherein a center of rotation of the tool iseccentric relative to a center of the IC component when separating theIC component from the board while turning the tool.

According to an eighth aspect of the present invention, there isprovided an IC component separating method based on any one of the firstthrough seventh aspects, wherein the board moves so that the board doesnot hinder the turning operation of the tool when the tool comes incontact with the board during the turning of the tool when separatingthe IC component from the board while turning the tool.

According to a ninth aspect of the present invention, there is providedan IC component separating apparatus for separating an IC componentmounted on a board from the board, comprising:

a tool formed with a contact portion that contacts the IC component andis able to move in a direction in which the IC component moves close toor apart from the board and turn so as to twist relative to a bondedsurface on which the IC component is bonded to the board; and

a heating device for heating the IC component or the bondingintervenient that bonds the IC component to the board, wherein thecontact surface of the tool is made to contact

the IC component mounted on the board, the bonding intervenient issoftened by heating the IC component or the bonded portion of the ICcomponent and the board by means of the heating device, and the ICcomponent is separated from the board by turning the tool so as to twistthe tool with respect to the bonded surface on which the IC component isbonded to the board.

According to a tenth aspect of the present invention, there is providedan IC component separating apparatus based on the ninth aspect, whereinthe heating device is provided for the tool and heats the IC componentor the bonded portion of the IC component and the board through heatconduction from the tool, the bonding intervenient is softened by thisheating, and the IC component is separated from the board by turning thetool so as to twist the tool with respect to the bonded surface on whichthe IC component is bonded to the board.

According to an eleventh aspect of the present invention, there isprovided an IC component separating apparatus based on the tenth aspect,wherein the heating device is an infrared light applying device forheating the IC component and the bonding intervenient of the ICcomponent with infrared light from a rear surface of the board.

According to a twelfth aspect of the present invention, there isprovided an IC component separating apparatus based on any one of theninth through eleventh aspects, wherein the tool is provided with asuction device that is able to make a negative pressure inside the tooland to suck the IC component or the bonding intervenient.

According to a thirteenth aspect of the present invention, there isprovided an IC component separating apparatus based on any one of theninth through twelfth aspects, wherein a center of rotation of the toolis eccentric relative to a center of the IC component when separatingthe IC component from the board while turning the tool.

According to a fourteenth aspect of the present invention, there isprovided an IC component separating apparatus based on any one of theninth through thirteenth aspects, comprising a retreating mechanism formoving the board so that the board does not hinder the turning operationof the tool when the tool comes in contact with the board while the toolturns when separating the IC component from the board while turning thetool.

The above tool is only required to be provided with the contact portionto contact the IC component and be able to move in a direction in whichthe IC component moves close to or apart from the board and to turn soas to twist relative to the bonded surface on which the IC component isbonded to the board.

According to the above separating method, the bonding intervenient issoftened by heating the IC component or the bonded portion of the ICcomponent and the board, and the IC component is separated while beingtwisted by the tool relative to the bonded surface on which the ICcomponent is bonded to the board, and therefore, the IC component can beseparated from the board with a relatively small force.

By making the heated tool cover the IC component, the bondingintervenient of the IC component and the board is softened, andtherefore, the IC component can be more easily separated from the board.

If the IC component is attracted by vacuum suction from the tool whenseparating the IC component from the board by turning the tool, then theIC component is sucked to the tool. This facilitates easy disposal ofthe IC component that has been sucked and removed, thereby improving thework efficiency. The IC component is removed from the board when turningthe IC component, and therefore, the bonding intervenient adhered on theIC component can be prevented from spattering onto the board during theturn.

If the IC component or the bonding intervenient is heated with infraredlight from the rear surface of the IC component bonding surface of theboard when separating the IC component from the board by turning thetool, the bonding intervenient of the IC component and the board can besoftened, and therefore, the IC component can be more easily separatedfrom the board.

Furthermore, by arranging the shield plate having the opening betweenthe infrared light applying device and the board and applying infraredlight to only the bonded portion to be separated through the openingwhen heating the IC component or the bonding intervenient with infraredlight, only the portion corresponding to the opening can be heated viathe shield plate, and therefore, this method can also be applied to fineIC components.

When heating the IC component as well as the bonding intervenient of theboard and the IC component with heated air from inside the tool andseparating the IC component from the board by turning the tool, it ispreferable to stop the heated air when the bonding intervenient issoftened or melted.

When mounting an IC component onto the board and thereafter separatingthe IC component by attaching the tape-shaped adhesive member to the ICcomponent to remove the IC component from the board, the IC componentcan be more easily removed by attaching the tape-shaped adhesive memberto the IC component and thereafter separating the IC component whileheating the IC component or its bonding intervenient with infrared lighton the rear surface side of the IC component bonding surface of theboard. member to the IC component and thereafter separating the ICcomponent while heating the IC component or its bonding intervenientwith infrared light on the rear surface side of the IC component bondingsurface of the board.

BRIEF DESCRIPTION OF DRAWINGS

These and other aspects and features of the present invention willbecome clear from the following description taken in conjunction withthe preferred embodiments thereof with reference to the accompanyingdrawings, in which:

FIG. 1A and FIG. 1B are respectively a schematic perspective view and apartial sectional view showing an IC component separating methodaccording to a first embodiment of the present invention;

FIG. 2 is a flowchart showing the IC component separating methodaccording to the first embodiment;

FIG. 3A and FIG. 3B are model charts used for calculating a separationforce of the separating method of the first embodiment;

FIG. 4 is a flowchart showing a mounting process of the IC componentseparating method according to a modification example of the firstembodiment;

FIG. 5A and FIG. 5B are respectively a schematic perspective view and apartial sectional view showing an IC component separating methodaccording to a second embodiment of the present invention;

FIG. 6 is a flowchart showing a mounting process of the IC componentseparating method of the second embodiment;

FIG. 7A and FIG. 7B are respectively a schematic perspective view and apartial sectional view showing an IC component separating methodaccording to a third embodiment of the present invention;

FIG. 8 is a flowchart showing a mounting process of the IC componentseparating method of the third embodiment;

FIG. 9 is a schematic sectional view showing an IC component separatingmethod according to a fourth embodiment of the present invention;

FIG. 10 is a flowchart showing a mounting process of the IC componentseparating method of the fourth embodiment;

FIG. 11 is a flowchart showing a mounting process of the IC componentseparating method according to a modification example of the fourthembodiment;

FIG. 12A and FIG. 12B are sectional views showing an IC componentseparating method according to a fifth embodiment of the presentinvention;

FIG. 13A and FIG. 13B are sectional views showing the IC componentseparating method according to the fifth embodiment of the presentinvention;

FIG. 14A, FIG. 14B, and FIG. 14C are schematic perspective views showingthe prior art IC component separating methods, respectively;

FIG. 15 is a longitudinal sectional view showing the prior art BGAcomponent separating method;

FIG. 16A and FIG. 16B are schematic plan views showing IC componentseparating methods according to the first embodiment and the sixthembodiment of the present invention;

FIG. 17A and FIG. 17B are respectively a schematic perspective view anda partial sectional view showing an IC component separating methodaccording to the sixth embodiment;

FIG. 18A and FIG. 18B are respectively a schematic perspective view anda partial sectional view showing an IC component separating methodaccording to a modification example of the sixth embodiment;

FIG. 19A and FIG. 19B are respectively a schematic perspective view anda partial sectional view showing an IC component separating methodaccording to a seventh embodiment of the present invention;

FIG. 20A and FIG. 20B are respectively a schematic perspective view anda partial sectional view showing an IC component separating methodaccording to a modification example of the seventh embodiment; and

FIG. 21 is a schematic plan view showing the IC component separatingmethods according to the seventh embodiment and the modification exampleof the seventh embodiment.

DETAILED DESCRIPTION OF

Before the description of the present invention proceeds, it is to benoted that like parts are designated by like reference numeralsthroughout the accompanying drawings.

The following will describe the IC component separating method andapparatus according to various embodiments of the present invention withreference to the drawings. It is to be noted that the same components asthose of the prior art are denoted by the same reference numerals, andno description is provided for them.

First, the IC component separating method and apparatus according to afirst embodiment of the present invention will be described withreference to FIG. 1 through FIG. 3.

As shown in FIG. 1A and FIG. 1B, a concave tool 21 serving as an exampleof a tool to be used for the present separating method is provided witha concave portion 21a located at the center of the lower surface thereofso as to have a pair of contact surfaces 21f, or contact portions thatare arranged opposite to each other to contact a pair of oppositesurfaces of an IC component 1, and the tool 21 is able to move in thevertical direction and to pivot around a vertical axial center O₁. TheIC component 1 is mounted on the board 3 comprised of a flat paneldisplay board or a circuit board by an anisotropic conductive film 2 inthis case. The mounted state in this case is not the completelycompression-bonded state in which the anisotropic conductive film iscompletely hardened but a temporarily compression-bonded state in whichthe anisotropic conductive film is not completely hardened. In thepresent embodiment, the tool 21 is driven to rotation by a rotary shaft100a of a motor 100, and the center of rotation (vertical axial centerO₁) roughly coincides with the center of the IC component 1.

When separating the IC component 1 from the board 3, there are performedthe processes of positioning the concave tool 21 just above the ICcomponent 1 in step #1 in FIG. 2, thereafter moving the concave tool 21down into a specified position to make the concave tool 21 cover the ICcomponent 1 mounted on the board 3 via an adhesive, solder, orconductive paste (step #2), and turning the concave tool 21 around thevertical axial center O₁ in a state in which the contact surfaces 21f ofthe concave tool 21 contact the opposite surfaces of the IC component 1(step #3), thereby separating the IC component 1 from the board 3.Subsequently, the concave tool 21 is moved up to separate from the ICcomponent 1 (step #4). Preferably, in order not to damage the board 3 bythe contact of the concave tool 21 with the board 3, it is appropriateto use a concave portion 21a of which the depth is adjusted so that thelower end surface of the concave tool 21 does not come in contact withthe board 3. In order to prevent the IC component 1 from separating fromthe concave portion 21a of the tool 21 when separating the IC component1 from the board 3 by rotating the IC component 1 by the tool 21, thedepth of the concave portion 21a is required to have such a dimensionthat at least one half of the height of the IC component 1 enters theconcave portion. Preferably, the tool 21 may be pressed by providing anurging portion for a support portion (not shown), the rotary shaft 100aof the motor 100 or the like.

Comparing this turning separation (see FIG. 3A and FIG. 3B) to thepushing separation as stated in connection with the prior art shown inFIG. 14A, the following results.

It is herein assumed, as a precondition of calculation, that an ICcomponent 1 of 20×2 mm is used. A twisting stress: τ_(max) is generatedat a point A on a longer side "a" and is expressed by the followingequation:

    τ.sub.max =τ.sub.A =T/(K·a·b.sup.2)

where T is torque, K is a shear modulus, "a" is the length of the longerside, and "b" is the length of the shorter side.

Therefore, the torque: T is expressed by the following equation:

    T=K·a·b.sup.2 ·τ.sub.max

where, by substituting τ_(max) =F/a/b into the above equation, there isobtained:

    T=K·b·F

where F is the shear modulus for pulling and sliding the IC component toseparate the IC component 1 from the board 3.

                  TABLE 1                                                         ______________________________________                                        a/b of Rectangular Sectional Area and Value of Coefficient                    ______________________________________                                        a/b    1.0    1.25      1.5  2.0    3.0  4.0                                  ______________________________________                                        K      0.208  0.221     0.231                                                                              0.246  0.267                                                                              0.282                                a/b    5.0    6.0       8.0  10.0   3.0  4.0                                  ______________________________________                                        K      0.290  0.299     0.307                                                                              0.312  0.267                                                                              0.282                                ______________________________________                                    

From Table 1, a/b=10 in the above model.

Therefore, K=0.312. On the other hand, since a force of not smaller than10 kgf is necessary for pulling and sliding the IC component 1 forseparation by a shear force according to experimental data, if it isassumed that F=10 kgf and respective constants are substituted into theabove equation, then the equation becomes:

T=0.312×2×10=6.24 kgf·mm. A distance from the center of rotation of theconcave tool 21 to the motor for driving this concave tool 21 is assumedto be 51 mm and T is divided for conversion into a force, then there is:

    F'=6.24/51=0.1224 kgf.

Consequently, F:F'=82:1. Therefore, the separation can be effected withrotative separation strength being 1/82 that of the push test.

More preferably, as shown in step #5 in FIG. 4, by heating the concavetool 21 and making this heated concave tool 21 cover the IC component 1,the IC component 1 and the anisotropic conductive film 2 are heated byheat conduction to soften the anisotropic conductive film 2. Then, byrotating the concave tool 21 in this state, the IC component 1 isseparated from the board 3. As described above, by heating the concavetool 21, the IC component can be more easily separated even in the statein which the anisotropic conductive film 2 is completely hardened (i.e.,in the aforementioned completely compression-bonded state). Itsexperimental data are shown in Table 2.

                  TABLE 2                                                         ______________________________________                                        Relation between Temperature of LSI Separating                                Concave Tool and Separation Strength after Complete                           Compression-Bonding                                                           Anisotropic                                                                   Conductive   Concave Tool Temperature                                         Film         25° C.                                                    Product Name (R, T)  100° C.                                                                          175° C.                                                                      250° C.                           ______________________________________                                        AC-830IZX-2-c                                                                              5.95    5.85      3.85  0.6                                      produced by                                                                   Hitachi                                                                       Chemical Co.,                                                                 Ltd.                                                                          Chip         x       x         x     o                                        Cracking                                                                      CP84301Q     4.9     5.6       3.15  0.9                                      produced by                                                                   Sony Chemicals                                                                Corp.                                                                         Chip         x       x         x     o                                        Cracking                                                                      ______________________________________                                         (Unit: kgf) Cracked: x Not Cracked: o                                    

The above data are those in the case where the anisotropic conductivefilm 2 is used for bonding the IC component 1 to the board 3. When thetemperature of the concave tool 21 was increased to 250° C., the ICcomponent 1 was able to be easily separated even after the completecompression bonding. However, according to the prior art separatingmethod shown in FIG. 14A, cracks were generated in all of the ICs orboards that were used for the experiment.

As described above, the IC component 1 can be separated with arelatively small force, and therefore, cracking of the IC component 1and damage to the board 3 can be suppressed to a minimum.

A second embodiment of the present invention will be described next withreference to FIG. 5A, FIG. 5B and FIG. 6. It is to be noted that thesame components and procedures as those of the first embodiment aredenoted by the same reference numerals and no description is providedfor them. In the second embodiment, the concave portion 21a of the tool21 is provided with a contact section 21f that contacts four sidesurfaces of the IC component 1 so as to cover the IC component 1 fromfour directions.

As shown in FIGS. 5A and 5B, the concave tool 21 is provided with asuction hole 21b connected to a vacuum suction path. This suction hole21b is connected to a vacuum suction device 115 via the vacuum suctionpath. Then, as shown in FIG. 6, the IC component 1 is separated byturning the concave tool 21 in step #4, and thereafter the IC component1 is sucked and held to the concave tool 21 by vacuum suction throughthe suction hole 21b (step #6). Then, the concave tool 21 is moved up instep #4, and thereafter the concave tool 21 is moved into a specifiedposition to stop the vacuum suction, thereby disposing of the ICcomponent 1 (step #7).

According to the above processes, the same effect and function as thoseof the first embodiment can be obtained, and the IC component 1 that hasbeen removed and sucked can be discarded and fragments of the ICcomponent 1 can be removed by suction, so that automatization can beachieved for the improvement in work efficiency. Furthermore, the ICcomponent 1 is separated from the board 3 when the IC component 1 isturned, and therefore, the anisotropic conductive film 2 that hasadhered on the IC component 1 can be prevented from spattering andadhering onto the board 3 during the turn.

Next, a third embodiment of the present invention will be described nextwith reference to FIG. 7A, FIG. 7B and FIG. 8. It is to be noted thatthe same components and procedures as those of the embodiments aredenoted by the same reference numerals and no description is providedfor them.

In FIG. 7A, reference numeral 22 denotes an infrared light applyingsection for applying infrared light, and 23 denotes a shield plate forshielding infrared light, where an opening 23a of an appropriate sizefor heating the anisotropic conductive film 3 is formed. Also in thisthird embodiment, the IC component 3 is bonded to the board 1 via abonding intervenient 6 (or intervening member) such as an anisotropicconductive film 2, conductive paste, or solder.

In this third embodiment, as shown in FIG. 7A and FIG. 8, the infraredlight applying section 22 is arranged on the rear surface side of theboard 3, and a heated concave tool 21 is moved down to cover the ICcomponent 1 (step #2). In this case, it is acceptable to heat theconcave tool 21 by a heater or the like and then heat the IC component 1and the bonding intervenient 6 through heat conduction by putting theconcave tool 21 in contact with the IC component 1. Then, with thisoperation, the shield plate 23 is inserted between the board 3 and theinfrared light applying section 22 (step #8), and infrared light isapplied through the opening 23a to the portion of the board 3 where theIC component 1 is mounted (step #9). Next, when the bonding intervenient6 is softened through heat conduction from the board 3 after a specifiedtime, the concave tool 21 is turned to separate the IC component 1 (step#3) and then the concave tool 21 is moved up to remove the separated ICcomponent 1. In this case, as shown in FIG. 7B, it is, of course,preferable to provide the concave tool 21 with a suction hole 21b andsuck the IC component 1.

According to this arrangement, the bonding intervenient 6 is softenedthrough not only the heating of the IC component 1 from its peripheryvia the concave tool 21 but also heat conduction from the board 3 withthe application of infrared light, so that the separating work can beperformed more easily. Since only the portion corresponding to theopening 23a can be heated via the shield plate 23, this method can alsobe applied to a fine IC component 1. When the board 3 is formed of atransparent material such as glass, the infrared light is transmittedthrough the board 3. Therefore, the softening of the bondingintervenient 6 can be achieved in a shorter time than when softening thebonding intervenient 6 is only achieved only through heat conduction, sothat the separation of the IC component 1 can be easily performed. Theinsertion of the shield plate into the specified position and theinfrared light applying operation are not limited to the steps #8 and#9, and they may be performed before or after positioning the tool 21just above the IC component 1.

A fourth embodiment of the present invention will be described withreference to FIGS. 9 through 11.

In this embodiment, as shown in FIG. 9, the concave tool 21 is providedwith a hole 21c, and heated air can be blown out of a heated air source120 through the hole 21c to the inside of the concave tool 21. Then, asshown in FIG. 10, the concave tool 21 is moved down to cover the ICcomponent 1 with a gap h provided between the upper surface of the ICcomponent 1 and the inner surface of the concave portion 21a of the tool21 (step #2), and thereafter heated air is blown from the hole 21c tothe inside of the concave tool 21 (step #10), thereby heating the ICcomponent 1 and the bonding intervenient 6 of the board 3 and the ICcomponent 1 with heated air. Next, in a state in which the bondingintervenient 6 is softened by continuing the heating with heated air fora specified time (step #11), the concave tool 21 is turned to separatethe IC component 1 (step #3).

As shown in FIG. 11, it is acceptable to soften the bonding intervenient6 by blowing heated air (steps #10 and #11), thereafter separating theIC component 1 by turning the tool (step #3), then moving the concavetool 21 down to the gap height h between the IC component 1 and theconcave tool 21 as shown in FIG. 8 thereby making the inner surface ofthe concave portion 21a of the concave tool 21 contact the upper surfaceof the IC component 1 (step #12), thereafter sucking the IC component 1by performing vacuum suction from the hole 21c (step #13) and moving upthe concave tool 21 thereby discarding the IC component 1. It is to benoted that 20 the timing in accordance with which the concave tool 21 ismoved down so as to eliminate the gap h is not limited to the time afterthe IC component 1 is separated, and the tool 21 may be moved downbefore the IC component 1 is separated by turning the tool 21.

Particularly, according to this system of blowing heated air from theconcave tool 21, heat can be applied to or around only a specifiedposition on the board 3, and therefore, less influence can be exerted onthe other components. Even when IC components are stacked in two layersas in the case of BGA and it is difficult to soften or melt the bondingintervenient 6 between the tool and the board 3 through only heatconduction from the concave tool 21, the heated air easily reaches theboard 3 and the bonding intervenient 6, so that the IC component 1 caneasily be separated.

A fifth embodiment of the present invention will be described next withreference to FIG. 12A, FIG. 12B, FIG. 13A, and FIG. 13B.

In this embodiment, as shown in FIG. 12A and FIG. 13A, a tape-shapedadhesive member 24 is attached to the IC component 1 mounted on theboard 3 and then the adhesive member 24 is pulled upward, therebyseparating the IC component 1 from the bonding intervenient 6 such as ananisotropic conductive film, conductive paste, or solder.

Preferably, as shown in FIG. 12A and FIG. 13A, this separating work caneasily be achieved by attaching the tape-shaped adhesive member 24 tothe IC component 1 after mounting the IC component 1 on the board 3 andthereafter separating the IC component 1 by applying heat with infraredlight to the IC component 1 or its bonding intervenient 6 from the rearsurface.

When the anisotropic conductive film 2 is used as the bondingintervenient 6 as shown in FIG. 12B and FIG. 13B, according to themethod of attaching the tape-shaped adhesive member 24 to theanisotropic conductive film 2 and separating the component 1 by means ofthe tape-shaped adhesive member 24 similar to the above case, thedisposal of the IC component 1 can easily be performed. When separatingand removing the bonding intervenient 6 such as the anisotropicconductive film 2 by the tape, the bonding intervenient 6 can easily beremoved without using the repair liquid, cotton swab and so on asdescribed in connection with the prior art nor spattering the bondingintervenient 6.

In each of the aforementioned embodiments, with regard to the shape ofthe concave tool 21, the tool is only required to be provided with acontact portion such that can turn the IC component 1 relative to theboard 3. The present invention is not limited to such a shape that isprovided with the four contact portions 21f to contact all the four sidesurfaces of the IC component 1 and entirely covers the IC component 1 asshown in FIG. 5A and FIG. 5B. The same effect can be obtained by a shapefor holding at least two sides out of the four sides of the IC component1, or, for example, a downwardly C-figured shape having two contactportions 21f to contact two opposite side surfaces of the IC component 1as shown in FIG. 1A and FIG. 1B.

As shown in FIG. 1A, FIG. 1B, FIG. 5A, FIG. 5B, and FIG. 16A, thepresent invention is not limited to the tool that turns while making therotary center O₁ of the tool 21 roughly coincide with the center of theIC component 1. It is acceptable to eccentrically turn the IC component1 by turning the tool 21 while displacing the center of rotation 02 ofthe tool 21 from the center of the IC component 1 according to a sixthembodiment of the present invention as shown in FIG. 16B, FIG. 17A, andFIG. 17B. Further, as a modification example of the sixth embodiment, asshown in FIG. 18A and FIG. 18B, it is acceptable to employ a linkmechanism provided with the rotary shaft 100c of a motor 100, a link 101whose one end is connected to the rotary shaft 100c, and a shaft 102connected to the other end of the link 101 and turn the tool 21eccentrically with respect to the center of the rotary shaft 100c of themotor 100.

When turning the tool 21 in the above embodiment, the board 3 is, inprinciple, prevented from being damaged so that the tool 21 does notcome in contact with the board 3. It is acceptable to retreat the board3, or in particular, the board 3 of a LCD or the like when the tool 21comes in contact with the board 3. As one example, according to aseventh embodiment of the present invention as shown in FIG. 19A, FIG.19B, and FIG. 21, a board support base 112 for supporting the board 3 isurged by a spring 110 so that a projection 112a of the board supportbase 112 always contacts a stopper 111 of a fixed base. With thisconstruction, the board 3 may be prevented from being damaged by thetool 21 by retreating as moving the board support base 112 in thedirection of arrow 156 against the urging force of the spring 110 whenthe tool 21 comes in contact with the board 3 in turning the tool 21. Asa modification example of the seventh embodiment, as shown in FIG. 20A,FIG. 20B, and FIG. 21, it is acceptable to provide a board support base153 on a fixed base 152, make the board support base 153 movable bylinear ways 150 and 151 that guide the straight movement of the boardsupport base 153, and move the board 3 in the direction 156 in which theboard 3 retreats when the tool 21 turns to come in contact with theboard 3.

In the aforementioned various embodiments, the drive source for turningthe tool 21 is not limited to the motor, and various known drive sourcessuch as a rotary cylinder may be used.

According to the present invention, the tool having the contact portionfor contacting the IC component is made to cover the IC componentmounted on the board, and this tool is turned so as to twist withrespect to the bonded surface on which the IC component is bonded to theboard, thereby allowing the IC component to be easily removed from theboard without damage to the board. This facilitates easy mounting ofanother IC component after removing the IC component and causes lessdamage on the board, therefore improving the reliability.

In heating the tool or by the heating with infrared light, the ICcomponent can be removed without causing damage to the IC component, andthe subsequent mounting can easily be achieved, therefore improving theproductivity.

According to the system of blowing heated air from the tool, heat can beapplied to or around only the specified position on the board, exertingno influence on the other components. When the IC components are stackedin two layers as in the case of BGA or the like, the IC components caneasily be separated even when the softening or melting of the bondingintervenient between the components and the board is difficult throughheat conduction from the tool.

According to the method of separating the IC component by making thetool attract by suction the IC component and turn while moving up, theIC component is separated from the board while the IC component isturned, and therefore, the bonding intervenient such as the anisotropicconductive film attached to the IC component can be prevented fromspattering onto the board during the turn.

According to the method of separating the IC component by means of thetape-shaped adhesive member, the disposal of the IC component can beachieved with each tape, so that the disposal can easily be achieved.When separating and removing the bonding intervenient by means of thetape, the bonding intervenient can easily be removed without using therepair liquid, cotton swab and so on as described in connection with theprior art.

The entire disclosure of Japanese Patent Application No. 8-93708 filedon Apr. 16, 1996, including specification, claims, drawings, and summaryare incorporated herein by reference in its entirety.

Although the present invention has been fully described in connectionwith the preferred embodiments thereof with reference to theaccompanying drawings, it is to be noted that various changes andmodifications are apparent to those skilled in the art. Such changes andmodifications are to be understood as included within the scope of thepresent invention as defined by the appended claims unless they departtherefrom.

What is claimed is:
 1. An IC component separating method for separatingan IC component mounted on a board via an intervening bonding member,the method comprising:contacting the IC component mounted on the boardwith at least a pair of opposite contact surfaces of a tool; heating theIC component or a bonded portion of the IC component and the board so asto soften the intervening bonding member; and separating the ICcomponent from the board by rotating the tool so as to twist the ICcomponent relative to a bonded surface on which the IC component isbonded to the board, wherein a center of rotation of the tool iseccentric relative to a center of the IC component when separating theIC component from the board while turning the tool.
 2. An IC componentseparating method as claimed in claim 1, wherein the intervening bondingmember is an anisotropic conductive film.
 3. An IC component separatingmethod as claimed in claim 1, further comprising heating the tool suchthat the IC component or the bonded portion of the IC component and theboard are heated by means of heat conducted from the tool when thecontact surfaces contact the IC component.
 4. An IC component separatingmethod as claimed in claim 1, further comprising vacuum suctioning theIC component to attract the IC component to the tool while separatingthe IC component from the board.
 5. An IC component separating method asclaimed in claim 1, wherein the IC component or the bonded portion ofthe IC component and the board is heated with infrared light projectedto a rear surface of an IC component mounting surface of the board whenseparating the IC component from the board.
 6. An IC componentseparating method as claimed in claim 5, wherein the infrared light isprojected from an infrared light applying device through an opening in ashield plate that is arranged between the infrared light applying deviceand the board, and the infrared light is projected, through the opening,only onto the bonded portion.
 7. An IC component separating method forseparating an IC component mounted on a board via an intervening bondingmember, the method comprising:contacting the IC component mounted on theboard with at least a pair of opposite contact surfaces of a tool;heating the IC component or a bonded portion of the IC component and theboard so as to soften the intervening bonding member; separating the ICcomponent from the board by turning the tool so as to twist the toolrelative to a bonded surface on which the IC component is bonded to theboard; and moving the board so that the board does not hinder theturning operation of the tool when the tool comes in contact with theboard during the turning of the tool so as to separate the IC componentfrom the board.
 8. An IC component separating method as claimed in claim7, wherein the intervening bonding member is an anisotropic conductivefilm.
 9. An IC component separating method as claimed in claim 7,further comprising heating the tool such that the IC component or thebonded portion of the IC component and the board are heated by means ofheat conducted from the tool when the contact surfaces contact the ICcomponent.
 10. An IC component separating method as claimed in claim 7,further comprising vacuum suctioning the IC component to attract the ICcomponent to the tool when separating the IC component from the board.11. An IC component separating method as claimed in claim 7, wherein theIC component or a bonded portion of the IC component and the board isheated with infrared light projected to a rear surface of an ICcomponent mounting surface of the board when separating the IC componentfrom the board.
 12. An IC component separating method as claimed inclaim 11, wherein the infrared light is projected from an infrared lightapplying device through an opening in a shield plate that is arrangedbetween the infrared light applying device and the board, and theinfrared light is projected through the opening to only the bondedportion.
 13. An IC component separating method for separating an ICcomponent mounted on a board via an intervening bonding member, themethod comprising:contacting the IC component mounted on a board with atleast a pair of opposite contact surfaces of a tool; heating the toolsuch that the IC component or the bonded portion of the IC component andthe board are heated by means of heat conducted from the tool when thecontact surfaces contact the IC component so as to soften theintervening bonding member; heating the IC component or the bondedportion of the IC component and the board with infrared light projectedonto a rear surface of an IC component mounting surface of the boardwhen separating the IC component from the board; and separating the ICcomponent from the board by turning the tool so as to twist the ICcomponent relative to a bonded surface on which the IC component isbonded to the board.
 14. An IC component separating method as claimed inclaim 13, wherein the infrared light is projected from an infrared lightapplying device through an opening in a shield plate that is arrangedbetween the infrared light applying device and the board, and theinfrared light is projected through the opening to only the bondedportion.
 15. An IC component separating apparatus for separating an ICcomponent from a board, said apparatus comprising:a tool having acontact portion for contacting the IC component, said tool being movablein a direction toward and away from the board on which the IC componentis mounted, said tool being able to rotate so as to twist the ICcomponent relative to a bonded surface on which the IC component isbonded to the board; and a heating device for heating the IC componentor an intervening bonding member bonding the IC component to the board,wherein the contact portion of said tool is formed so as to contact theIC component mounted on the board, the intervening bonding member issoftened by heating the IC component or a bonded portion of the ICcomponent and the board by means of said heating device, and the ICcomponent is separated from the board by rotating said tool so as totwist the IC component with respect to the bonded surface on which theIC component is bonded to the board, and wherein a center of rotation ofsaid tool is eccentric relative to a center of the IC component whenseparating the IC component from the board while rotating the tool. 16.An IC component separating apparatus as claimed in claim 15, whereinsaid heating device is provided for heating the tool so that the ICcomponent or the bonded portion of the IC component and the board isheated through heat conduction from the tool.
 17. An IC componentseparating apparatus as claimed in claim 16, wherein said heating devicecomprises an infrared light applying device for heating the IC componentand the intervening bonding member of the IC component with infraredlight from a rear surface of the board.
 18. An IC component separatingapparatus as claimed in claim 16, wherein said tool is provided with asuction device that is capable of producing a negative pressure insideof said tool to suck the IC component or the intervening bonding member.19. An IC component separating apparatus as claimed in claim 16, whereina center of rotation of said tool is eccentric relative to a center ofthe IC component when separating the IC component from the board whilerotating the tool.
 20. An IC component separating apparatus forseparating an IC component from a board, said apparatus comprising:atool having a contact portion for contacting the IC component, said toolbeing movable in a direction toward and away from the board on which theIC component is mounted, said tool being able to rotate so as to twistthe IC component relative to a surface on which the IC component isbonded to the board; a heating device for heating the IC component or anintervening bonding member that bonds the IC component to the board,wherein the contact portion of said tool is formed so as to contact theIC component mounted on the board, the intervening bonding member issoftened by heating the IC component or a bonded portion of the ICcomponent and the board by means of said heating device, and the ICcomponent is separated from the board by turning the tool so as to twistthe IC component with respect to the surface on which the IC componentis bonded to the board; and a retreating mechanism for moving the boardso that the board does not hinder the turning operation of said toolwhen the tool comes into contact with the board while the tool turns toseparate the IC component from the board.
 21. An IC component separatingapparatus as claimed in claim 20, wherein said heating device isprovided for heating the tool so that the IC component or the bondedportion of the IC component and the board can be heated through heatconducted from said tool.
 22. An IC component separating apparatus asclaimed in claim 21, wherein said heating device comprises an infraredlight applying device for heating the IC component and the interveningbonding member of the IC component with infrared light from a rearsurface of the board.
 23. An IC component separating apparatus asclaimed in claim 20, wherein said tool is provided with a suction devicethat is capable of producing a negative pressure inside of said tool andsucking the IC component or the intervening bonding member.